LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Waveform chart update time

Hi all,

 

I have a VI with one while loop that generates an array of measurements at a specific rate (to simulate the acquisition rate of an FPGA I am interfacing with). A second loop displays the data in a chart and records it to a file. I am using queues to transfer the data between the two loops. The simulator generates 10,000 points every second, this cannot be changed (see VI).

 

I need the chart to update more often than once per second, which is what it is doing now. By that I mean more fluidly, so it looks like data is just running across the chart rather than chunks being added to it. It does not need to be real-time.

 

I know the problem is that the waveform is added to the chart 1 second/update, but I'm not sure what the best way of fixing it would be. I tried the resampling VI but it still updated the chart once every second.

 

The VI is attached.

 

Any help in solving this would be appreciated.

 

Thanks,

 

Ilya.

Download All
0 Kudos
Message 1 of 4
(3,538 Views)

The graph is updating once a second because that is how often you are passing data to the queue that the driving the chart.

 

A more basic problem is your expectations. You are not going to send 10000 points to a chart every second and get something that scrolls "fluidly".

 

Mike...


Certified Professional Instructor
Certified LabVIEW Architect
LabVIEW Champion

"... after all, He's not a tame lion..."

For help with grief and grieving.
0 Kudos
Message 2 of 4
(3,517 Views)

You may need to break the waveform into smaller chunks after the queue, and drip feed it via another queue to a display (chart) loop, that reads it at, say 10 Hz. You may be able to use the #elements in queue to programmatically adjust the timing of this loop to just keep up with incoming data.

0 Kudos
Message 3 of 4
(3,513 Views)

Yes, you could do that, but the basic problem remains that updating 1000 points at a time will not give a fluid display.

 

Mike...


Certified Professional Instructor
Certified LabVIEW Architect
LabVIEW Champion

"... after all, He's not a tame lion..."

For help with grief and grieving.
0 Kudos
Message 4 of 4
(3,510 Views)